A modern multi-core processor, such as an Intel® architecture processor or another brand processor, generally has multiple power states available to allow for power conservation when the processor is not busy. The voltage supplied to the processor and the frequency of the processor may be dynamically modified during operation based on a number of factors such as the current power state of the processor. It is generally beneficial to have a stable and unchanging voltage supplied to a clock signal generation circuit, such as a phase locked loop (PLL), when the PLL is in the process of modifying (e.g. relocking) the frequency of the clock signal being output. Asynchronous voltage changes during this time may disrupt a PLL lock process.